NEAR-FIELD RANGE EVALUATION TESTING USING NIST 18 TERM ERROR MODEL
Any antenna range, near-field or far-field, is subject to error sources which must be carefully analyzed or evaluated. The near-field industry has adopted an evaluation technique based on a set of error terms first proposed by NIST (“Error Analysis Techniques for Planar Near-field Measurements”, IEEE Trans. Antenna and Prop. Vol. 36, no. 6, June 1988, by Allen Newell).
These 18 terms are typically evaluated by a combination of analysis and tests. NSI has extensive experience in performing complete range evaluations for gain, side lobes levels, cross-pol levels, and beam pointing errors. During system installation and training, we typically include a brief overview of the range evaluation process. A complete range accuracy evaluation including all testing, analysis, and summary report can be quoted as an optional service.
The following table shows an example of the results of the range evaluation on one of NSI’s large near-field ranges used for testing the Globalstar satellite antennas.